Bug 1257058
| Summary: | Libxslt 1.1.28 Type Confusion vulnerability may cause DOS | ||||||
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| Product: | [Other] Security Response | Reporter: | puzzor <puzzorsj> | ||||
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> | ||||
| Status: | CLOSED DUPLICATE | QA Contact: | |||||
| Severity: | low | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | unspecified | CC: | scorneli, vkaigoro | ||||
| Target Milestone: | --- | Keywords: | Security | ||||
| Target Release: | --- | ||||||
| Hardware: | All | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2015-09-21 11:27:32 UTC | Type: | Bug | ||||
| Regression: | --- | Mount Type: | --- | ||||
| Documentation: | --- | CRM: | |||||
| Verified Versions: | Category: | --- | |||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||
| Embargoed: | |||||||
| Bug Depends On: | |||||||
| Bug Blocks: | 1257962 | ||||||
| Attachments: |
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*** This bug has been marked as a duplicate of bug 1257962 *** |
Created attachment 1067176 [details] corrupt xml file Description of problem: Version-Release number of selected component (if applicable): 1.1.28 How reproducible: ./xsltproc poc Actual results: Denial of Service Expected results: Additional info: Function "xsltStylePreCompute" in preproc.c may cause a denial of service, the root cause is a type confusion. Through analysis we get to know that parent->ns->href in line 2250 of preproc.c is an invalid value with our poc. The whole process is as follow: 1> The main function in xsltproc.c will call xmlReadFile to read a .xml file. xmlReadFile will return a xmlDocPtr which points to the xmlDoc. When we print xmlDocPtr->children->parent->ns, its value is 0xffffffff. Obviously, this value is not a correct one. 2> Later in xsltStylePreCompute of preproc.c, the function will see whether current element is 'attribute', if yes,if inst->parent!=NULL and parent->ns!=NULL, then it will call xmlStrEqual, the first parameter is a ptr but its value is 0xffffffff! 3> We went further into libxml and see why this happened.The result is : in SAX2.c +2293 of libxml, we found that the first parameter "ctxt->myDoc" is a xmlDocPtr, but it will be teated as a xmlNodePtr. Obviously, xmlDoc and xmlNode have different structure. This is why "xmlDocPtr->children->parent->ns" get a invalid value(0xffffffff), this value comes from xmlDoc->compression. Possible Patch: Add a judgement in preproc.c+2248, before call xmlStrEqual we must determine whether parent->type equals XML_DOCUMENT_NODE